Clutch actuator and adjuster



Jan. 4, 1949. FOSTER 2,458,364

CLUTCH ACTUATOR AND ADJUSTER 7 Filed May 26, 1943 5 Sheets-Sheet l gwgoz/rvboc Jan. 4, 1949. E. E. FOSTER CLUTCH ACTUATOR AND ADJUSTER 5 Sheets-Sheet 2 Filed May 26, 1945 Jan. 4, 1949. FOSTER 2,458,364

CLUTCH ACTUATOR AND ADJUSTER 5 Sheets-Sheet 3 Filed May 26, 1943 1) lg? 2 1 T "mmmu m mumiwm w \IQHWHWEWWZIE I Jan. 4, 1949. FOSTER 2,458,364

CLUTCH ACTUATOR AND ADJUSTER 7 Filed May 26, 1945 5 Sheets-Sheet 4 gvwem/bom Z5 Edwnz E. Foster w w m Jan. 4, 1949. E, E Q 2,458,364

CLUTCH ACTUATOR AND ADJUSTER Filed May 26, 1943 5 Sheets-Sheet 5 gran/WM,

all/v4 17 E. Fast r? Patented Jan. 4, 1949 UNITED STATES PATENT O FFICE CLUTCHACTU'ATOR AND ADJUSTER EdwinE. Foster, Austin, Tex.

Application May 26., 1943, Serial No. 488,605

8 Claims.

This invention relates to an actuator forany operating mechanical device such :as forinstance the clutch of a vehicle, boat, or any other type of apparatus, machine or device. Thus'while the actuator is applicable to any .type of device or vehicle it is described and illustrated as applied to a clutch operating mechanism for a military vehicle such as a tank or armoured car.

It is therefore an object of this invention to provide a clutch operating mechanism with a device which will enable the operator to operate the clutch with the least efiort possible commensurate with the properand necessary opera tion of the vehicle. The invention permits the elimination of approximately two-thirds of the clutch pedal effort and -a more compact unit which is completely out of the driver's way and still is incorporated in the clutch actuating system. Another advantage of the invention resides in the simple applicability to existing clutch actuating systems or devices as an added unit which is easily applied to Vehicles already built and in use.

A further object of the invention resides in the adjustment features to compensate for wear which device is a separate .unit which may be easily operated from the driver's seat 'when-anadjustment in the operation of'the clutch pedal seems necessary.

Another object of the invention resides in the provision of a special template or guide member which is for the purpose of marking the shaft to make it possible to apply'an actuator clamp on the shaft in the proper position.

Further objects will be apparent from the following description when considered'in connection with the accompanying drawings, in which:

Figure 1 is a side elevation of the clutcha'ctuator in the normal or clutch-engaged position with the clutch pedal at the'top of its stroke of movement,

Fig. 2 is a View similar to Fig. 1 with the .parts in the clutch-disengaged position with the clutch pedal at the bottom of its stroke,

Fig. 3 is a top plan view partly in sectionof the actuator of Fig. 1 with certain partsomitted.

Fig. 4 is an end view of Fig. 1 with some of the parts omitted,

Fig. 5 is a plan view partly in section of a ball bearing receiving cup,

Fig. 6 is an end view of a slotted bracket.

Fig. '7 is a plan view of one form of template used to install the actuator,

Fig. 8 is an end View of the'template,

Fig. 9 is a plan view of a clutch pedal'linkage without the actuator and adjuster,

Fig. 10 is a plan view of an adjustor unit for the clutch pedal linkage,

Fig. 11 is a longitudinal sectional View of the adjustor unit.

Fig. 12is a perspectiveview oftheclutchapedal linkagesystem with theactuatorand adjuster connected inthe system,

Fig. 13 is aside elevation of a,:portion .of-t-the actuator showing another.iormrofitemplatein-ithe position of .use,:and

Fig. 14 is a top plan view partly :inxsection :of the actuator of Fig. 1'3.

Fig. .9 shows diagrammatically theclutchnperating system without the.inventiomapplied1thereto as applied to a vehicle such :asiamilitaryztank, in which clutch pedal l5is pivoted atihearin'g IFS and operates an arm H by means -':of :arrod 51.8. The arm I! is securely mounted .ODJFEI, .TCIOSSiShEfiJ Hi, the latter of which aisrotata'blezin suitable bearings 28 and 2|. A rodii22is connected rat=23 to the shaft [.9 and'.this=:rod "operates-a thrust bearing, not showngof a clutchcbyimeans'of' suitable elements. Fig. 12 illustrates.thesactuatorizu and the .adjustor .25 applied ate the linkagesystem. A tension link 26 is connected at one end=torthe adjustor 25 applied tothe linkage system,-iand the other end to one end of an arm' 2'l piv0ted.aat"28. The other end of the armllis pivotallyzc'om .nected to a compression link 29, whichflatter:=is

connected to a fork memberfifl having a thrust bearing 35 pivotally mounted therein. .Fig.112 therefore illustrates where the -actuator-andsadjustor are mounted in a clutch operating system of the type shown in Fig. 9, but it"is-.:of :course understood that the actuator and adjustor may be mounted at other suitable 'points-"in'zthe linkage system.

Referring now to Figs. 1 te l 'theactuator -M-is completely enclosed to keep outdust, 'dirt and other objects. A frame 32 consists of asuita'bIy dimensioned strap iron member bent :in'to the shape of a polygon, Figs. "land 2, with' top portion 33, side portions '34-and 35,-and bottom 'portion36ythe latter having perforations 31 therein, one man extendedpart 38,'by means'of-which, with the aid of bolts,not shown, the actuator-is secured to the vehicle.

A back wall or side plate 39 is welded to the :frame 32, in orderto enclosethe mechanism and make the box frame perfectly rigid. The bolt holes 3'! are the same distance'apart and the=same distance from the shaft I9 as the bearing support 2|, Fig. 9, which this boxframereplaces. *A ball bearing 40 is mounted 'in-a' bearing support block ll which carries a load-of 'the"cross=shaft 19. A split clamp member 42 grips theendio'f the shaft 1 9, due to the tightening bo1t'4'3 and the lock nut 44. A double arm or forkmember-4 1"integral with the clamp 42 supportsa ball bearing 45,by means of a pin lt, and a stamped metalcupWBfits into the endof a compression spring "49 an'dis provided with a recess 5B'WhiChfitSfhe outerraceof the ball bearing 45. 'IdenticaLpivot arrangements, a ball bearing 53 and a"meta1*cup"48,'are provided 3 on the opposite end of the compression spring 49, in order to pivotally connect the Spring to the double ears or lugs 5| of a slotted bracket 52. A slot 95 in the bracket 52 allows the latter to be moved back and forth in order to adjust the tension of the spring 49, to thereby adjust the load on the spring by means of an adjustment screw 54' threaded in the side portion 34 of the frame 32.

The under surface part 9| of the top of the box frame 24 where the bracket 52 slides is made parallel to a line between the center of a pivot pin 55 and the center of the shaft l9, which is important as the spring 49 must be adjusted to fit different clutches and the pin 55 must move on the center line in order not to disturb the dead center-position after the clamp 42 is located and fixed on the shaft I9. By locating the actuator on the end of the shaft l9 farthest away from the clutch pedal and by making the actuator do twothirds of the clutch pedal work, the remaining third is the only load on the bearings ahead of the actuator during the downward stroke of the pedal; and on the release stroke of the pedal no load is carried through the bearings and pins at the pedal end Of the linkage system. Due to the close proximity of the tension link 25 to the end of the shaft I9, Fig. 12, carrying the actuator clamp, the distortion in the shaft due to the actubolt 54 the bracket 52 is maintained in adjustedposition. Also the adjustment screw 54 is provided with a locking nut 56 to lock the screw 54 in position.

A closure plate 51, Figs. 3 and 4, may be removably secured to the side of the box opposite the permanent side plate 39.

The actuator may of course be built into a vehicle as the latter is manufactured and assembled. If, however, the actuator is to be installed into an existing vehicle, a part of the clutch operating members of which is shown in Fig. 9, the following procedure may be carried out.

The bearing support post 21 is first removed and the box or housing 32 of the actuator 24 is bolted to the floor of the vehicle by means of the two bolts formerly used to secure the post 2|. The end of the cross shaft l9 will extend through the bearing 40 about one inch, and the split clamp 42 fits loosely over the end of the shaft. In order to determine the location at which the clamp 42 should be tightened, a thin metal template 59 or 60, shown in Figs. 7, 8 and 13, is provided with each actuator. This metal template is to be held. in the corner of the box or frame 32, Fig. 13, over the end of the shaft and the end of the shaft is marked in a slot 58 in the template, with the clutch pedal held at the bottom of the free-play stroke. This free play stroke usually amounts to about 2", but is different on different clutches. The purpose of the free play is to allow the thrust bearing in the clutch to be entirely disconnected when-the pedal is at its top position. When the shaft has been marked with the template at the time the pedal is held at the bottom of the free play, the ,slot in the clamp should line up with this mark on the end of the shaft.

Figs. 13 and 14 illustrate a modified form of template in position for use. The template 60 has a slot 6| which is exactly in line with the center line between the points 62 and 63, which is the dead center position of the spring. The shaft I9 is marked through the slot 6| when the clutch 4 pedal is at the bottom of its free play stroke. This is in order that when the template is then removed and the clamp 42 tightened on the shaft I9, so that the slot in the clamp lines up with the mark, the springs in the clutch itself will always return the actuator to the dead center position.

It must be remembered that when an actuator is to be installed in the floor of a tank in which space is taken up by a number of elements like the transmission, the seats, etc., it is necessary for the mechanic who is installing this device to stand on his knees in a cramped position, and therefore, unless a template is used for marking the shaft, the clamp is apt to be fitted at a wrong position. Of course, it is possible to make this template in a number of different ways. For instance, it might be provided with a lug or finger 64, Figs. 13 and 14, which would insure the template staying firmly against the corner of the actuator housing, rather than depend on the mechanic to hold the template firmly against the corner.

In order to load the spring 49, the nut 55 is loosened and the set screw 54 backed off until the bracket 52 has moved as far to the left as it can go. Then with the pedal held all the way down, the slot 65 in the clamp 42 is lined up with the mark made on the end of the shaft l9, and the clamp bolt 43 is tightened. If necessary the lock nut 44 can be backed off against the wall in order to help compress the spring 49 and force the clamp clockwise about the shaft 19 until the slot lines up with the mark, after which the lock nut 44 should be tightened. With the pedal still held down, the adjustment screw 54 is tightened until the proper load is built up in the compression spring. The proper amount of load in the spring is determined by releasing the clutch pedal to see if the clutch returns freely. If it does not return freely, the adjustment screw 54 should be backed off until the clutch has the proper feel on the return. The screw 54 should then be tightened to grasp the bracket 52 and the lock nut 56 should also be tightened .to maintain the proper adjustment. The operation of the actuator when installed is as follows:

In the position shown in'Fig. 1, that is, with v the pedal at the top of its stroke, the actuator serves to hold the clutch pedal at the top of the stroke with sumcient force to enable the driver to ride the clutch pedal withabout fifty pounds force without moving the clutch pedal. This foot-rest feature is required-in order to prolong thelife of the thrust bearing. When the driver wishes to disengage the clutch he must supply slightly more than the fifty pounds at the beginning of the stroke. As the pedal moves through the free pedal stroke, the resistance offered by the actuator reduces to zero, as the pin 46 approaches the center line 62, 63, Fig. 13,

or the dead center position. At that point they load of the clutch itself (which amounts to about top of the pedal stroke of 55 pounds, and the exotic remainder of the stroke had a-maximum of 45 pounds. This 45 pounds was the load nearer the dead 'ceriter positio n. EventhisWan'belowered, if desired, by changing -tl ie angle of the adjustor 25 on the cross-shaft to give more leverage at the beginning of the pedal stroke and less at the end.

Wear in the clutch facings itself aife'ctsf this actuator in the following manner: The springs (not shown) in the clutch'help return the' s'pring 4-9 from the position shown in Fig.2 to thed'ead center position, after which the pull-backs'pring 66, Fig. 12, helps carry the spring 49 across the dead center position, where the 'sprin'g ls will help hold the pedal in the extreme upper po'sition. As the clutch wears, the clutch spring-s will help restore the spring 49 not onlyto-the dead center position, but slightly'pastit. The more wear that occurs, the further it will-help it above dead center. 7 cause the operator to notice an increase in the effort required near the beginning of the pedal stroke. It is this condition which makes it advisable or necessary to incorporate an easily'operated clutch adjustor, to restore the original correct relation of the clutch springs to the clutch actuator, by lengthening the pull link 26. The clutch adjuster shown in Figs. 10 and 11, performs the same function as a turnbuckle placed in the link 26. However, the clutch adjustor 25 makes it possible for the driver to make an adjustment in a few seconds without the use of tools and without having to remove the cover from the housing which encloses the pull link 26 and the propeller shaft, which is directly above the pull-link.

The clutch adjustor 25 consists of a sliding block 67 moving in a slot 68 in the parallel tension bars 69 by means of a threaded screw member 19. The screw member 10 is provided with a notched handle wheel H on which contacts the free end of a leaf spring 12 secured to the block 6? by means of rivets 13 to form a locking device. A small hole 14 is provided in the leaf spring in line with a shaft 15 so that the shaft 15 can be punched out through the opposite hole after a screw 16 has been loosened and a cut-away portion in a washer H has been moved around to line up the shaft hole. To install this adjustor, the clevis l8, Fig. 9, is removed from the arm 23 and the actuator screw threaded onto the shaft 26 and the hardened pin it placed through a hardened sleeve which is made to fit the hole in the member '23 to which the clevis 18 was originally connected. The adjustor should be installed when the screw H3 is screwed almost completely in, as shown in Fig. 10. As the clutch wears the driver will unscrew the threaded adjustment screws H to lengthen the distance between the shaft I 9 and the pull link 26. The hand knob TI on this adustor is made to extend a few inches ahead of the pin 75 in order that the driver can reach it in the space allowed in the vehicle.

I claim as my invention:

1. A device for aiding the operation of a spring urged clutch of a vehicle and the like comprising a frame secured to the vehicle and operatively connected to a shaft of a clutch operator, a bracket mounted on the frame, a clamp member secured on the shaft, and a compression spring mounted between the bracket and the clamp member to assist the operation of the clutch by overcoming a part of the force exerted by the clutch spring.

This condition would.

bearing m mber se'd' ed' to "the frar-ne in which a shaft-e cifitch operator rotates, a bracket adjustably seciired' to a side er the frame, a 'clamp memberseculred on nearer-ma pair o'fball beari'rigs, one mounted l n the bracket and the oth'e'r on th clamp memberfland a compres''s'i'onspring provided between-the ballfloearing's, said spring being shiftable by means of sereshaft-when the latter-is rotated tipon actuation of the clutch" to thereby eliminate apart *of tire-*taifbrt required to operate the clutch.

3.- ia' deiiice 'for aiding the operations-f a clut-ch or a irehicleai'id'the like com'pris ing a frame in the 's ape er a p'oiygen 'secured to the've'hiclaa bearing--member "secured to the frame in which a sharper a clutch op'era'tor' rotates, a' bracket adjustably s'cnred to a 'side' of" the frameya clamp member secured on the shaft, "a -pair of ball beariii'gso'ne' mounted' on' the bracket and the other on the' clanip"-'meriiber, a'fo'rk inember integral with the clamp member and to which'i'ts'ball bearing moufited and a compression spring provided between the ball bearings, said spring being shiftable by means of said shaft when the latter is rotated upon actuation of the clutch to thereby eliminate a part of the effort required to operate the clutch.

4. A device for aiding the operation of a clutch of a vehicle and the like comprising a frame secured to the vehicle, a bearing member secured to the frame in which a shaft of a clutch operator rotates, a bracket secured to the frame, a clamp member secured on the shaft, a pair of ball bearings, one mounted on the bracket and the other on the clamp member, and a spring provided between the ball bearings, said spring being shiftable by means of said shaft when the latter is rotated upon actuation of the clutch to thereby eliminate a part of the effort required to operate the clutch.

5. A device for aiding the operation of a clutch of a vehicle and the like comprising a frame secured to the vehicle, a bearing member secured to the frame in which a shaft of a clutch operator rotates, a bracket secured to the frame, a clamp member secured on the shaft, a pair of ball bearings, one mounted on the bracket and the other on the clamp member, a fork member integral with the clamp member and to which its ball bearing is mounted, and a spring provided between the ball bearings, said spring being shiftable by means of said shaft when the latter is rotated upon actuation of the clutch to thereby eliminate a part of the effort required to operate the clutch.

6. A device for aiding the operation of a clutch of a vehicle and the like comprising a frame in the shape of a polygon secured to the vehicle, a bearing member secured to the frame in which a shaft of a clutch operator rotates, a bracket adjustably secured to a side of the frame, a clamp member secured on the shaft, a pair of ball bearings, one mounted on the bracket and the other on the clamp member, a compression spring provided between the ball bearings, said spring being shiftable by means of said shaft when the latter is rotated upon actuation of the clutch to thereby eliminate a part of the effort required to operate the clutch, and means mounted in the frame for adjusting the bracket relative to the frame.

7. A device for aiding the operation of a clutch of a vehicle and the like comprising a frame secured to the vehicle, a bearin member secured to, the frame in which a shaft of a clutch opera tor rotates, a bracket adjustably secured to the frame, a clamp member secured on the shaft, a pair of bearings, one mounted on the bracket and the other on the clamp member, and-a spring provided between the bearings, said spring being shiftable by means of said shaft when the latter. is rotated upon actuation of the clutch to thereby eliminate a part of the effort required to operate the clutch. 8. A device for aiding the operationof a clutch of a vehicle and the like comprising a frame sea cured to the vehicle, a bearing member secured to the frame in which a shaft of a clutch operator rotates, a bracket secured to the frame, a clamp member secured on the shaft, a pair of ball bear: ings, one mounted on the bracket and the other on the clamp, and a resilient force applying means provided between the ball bearings, said means being shiftable by said shaft when the latter is rotated upon actuation of the clutch to thereby eliminate a part of the efiort required to operate theclutch. 1

. EDWIN E. FOSTER.

REFERENC S orrnn PATENTS UNITED STATES Number Name Date 602,586 Morris Apr. 19, 1898 v 737,560 Nunnally Aug, 25, 1903 1,171,341 Huff Q Feb. 8, 1916 1,804,903 Wemp. 1 May 12, 1931 1,360,636 Tibbetts May 31, 1932 1,927,613 Hughes Sept. 19, 1933 2,072,010 Moorhouse Feb. 23, 1 937 2,073,705 Moorhouse Mar. 16, 1937 2,096,151 Watt Oct. 19, 1937 2,171,385 Zeidler Aug. 29, 1939 2 ,177,052 Blough Oct. 24:, 1939 2,234,459 Wemp Mar. 11, 1941 v FOREIGN PATENTS Number Country 9 I "Date 23,267 British Oct. 28, 1908 

